ANEURYSM@RISK is an observational study aiming to develop and validate an artificial intelligence (AI)-based prediction model for the growth and rupture of intracranial aneurysms (IAs). By applying automated 3D segmentation and morphological quantification of IAs from MR angiography (MRA) scans, the model is intended to provide clinicians with objective and reproducible risk estimates of aneurysm instability.

The study utilizes retrospective imaging data from multiple European centers, including UMC Utrecht, AP-HP Paris, and University Medical Center Hamburg-Eppendorf (UKE). A clinical vignette study will evaluate the model's clinical utility and user experience among interventional radiologists.

This study is exempt from medical ethics review (non-WMO in the Netherlands), as it involves only existing, anonymized data and imposes no additional burden on patients.

The ANEURYSM@RISK study is part of the SHERPA project (Smart Human-centred Effortless support for Professional clinical Applications). The study aims to develop and validate a multivariable artificial intelligence (AI)-based prediction model to identify unstable unruptured intracranial aneurysms (UIAs), using morphological and clinical features.

Retrospective MR angiography (MRA) data will be collected from three clinical sites: UMC Utrecht (The Netherlands), AP-HP Paris (France), and University Medical Center Hamburg-Eppendorf (Germany). The study workflow includes:

• Development of AI algorithms for 3D shape feature extraction after automated aneurysm segmentation
• Training of predictive models for aneurysm growth and rupture based on morphological and clinical parameters
• Validation of model performance using a longitudinal dataset of ~1,000 patients (target C-statistic ≥ 0.80)
• A clinical vignette study in real-life settings to evaluate usability, decision-making impact, and inter-clinician variability

Key Performance Indicators (KPIs):

• Discriminative performance for aneurysm instability prediction; C-statistic ≥ 0.80
• Sensitivity ≥ 80% and specificity ≥ 50% (based on optimal cut-off values)
• ≥ 25% reduction in time to clinical decision-making
• ≥ 80% adherence to AI-generated suggestions by interventional radiologists
• ≥ 20% improvement in user experience using 3D visualization compared to 2D displays (survey-based)
• ≥ 50% reduction in inter- and intra-observer variability in aneurysm assessment

Ethical Considerations:

This is a non-interventional, retrospective study using previously acquired and anonymized imaging data. No additional procedures or data collection will be performed. The study poses no added burden or risk to patients. According to Dutch regulations, it is not subject to the Medical Research Involving Human Subjects Act (non-WMO).

Inclusion Criteria:

• Available MR angiography (MRA) scans of the Circle of Willis
• Presence of at least one intracranial aneurysm (IA)
• Availability of follow-up imaging or clinical records indicating stability, growth, or rupture

Exclusion Criteria:

• Imaging of insufficient quality for segmentation or analysis
• Lack of follow-up data

Adults with diagnosed unruptured intracranial aneurysms (UIAs) identified through MR angiography imaging, with follow-up records, from three European academic hospitals. All data are retrospective and anonymized.

De-identified participant-level data derived from imaging, including intracranial aneurysm morphological measurements and risk predictions, will be shared upon reasonable request from qualified investigators.

The individual participant data (IPD) and supporting documentation will be available after the publication of the main study results. The end date for availability has not yet been determined.

Only qualified academic researchers may request access for non-commercial purposes. Requests must include a description of the intended use and can be directed to: p.j.groenheide@umcutrecht.nl.